Hi Poppagator; I thought about that, but came up with the answer that the pins are so tightly fitted to the bridge plate that they are effectively part of it. The pins and the bridge plate are therefore a single body for acoustic purposes, and vibrate together as governed by the combined mass. Imagine if the bridge pins were glued in, and you get the idea. I wasn't joking about the oscilloscope; I'm going to set something up and report back. From what I know already, the main transmission of sound is via the point of highest vertical pressure on the string, which is at the saddle, not the pins. This pressure drives the bridge plate (including the pins), which transfers energy to the top. What seems to make the biggest difference here is the 'break angle' of the strings over the saddle. There is also some sound from the strings moving air over the soundhole. I think I'm actually agreeing with you; the brass pins will cause the acoustic properties of the bridge plate to change; but by adding mass, not by vibrating as a separate acoustic body.